Asymmetrical henry reaction of three dendate ligands of amino sugar derivatives Via Cu(II) ions

In this study, D-glucose and D-galactose were used as starting sugar. Firstly, the experimental works were constituted on the simple synthesis of the 6-amino derivatives of 1,2-O-(R)-trichloroethylidene-α-D-glucofuranose (α-chloralose) and 1,2-O-(S)-trichloroethylidene-α-D-galactofuranose. The trichloroethylidene acetals of D-glucose and D-galactose were prepared from the reaction of sugars and anhydrous chloral. Tosyl derivates of trichloroethylidene acetals of D-glucose and D-galactose were obtained through the reaction of these compounds with p-toluenesulfonylchloride and then, these tosyl derivates were converted to the azide form by following nuclephilic substitution reaction. Obtained azide derivates were reacted with triphenylphosphine as reducing agent in order to get the related amino-sugars derivates. Also the same amino-sugars were synthesized in the C-3 hydroxy groups are methylated to derivatives by the same method. Then, in order to synthesize Schiff bases; the homogeneous mixture aqua form of aldehyde (salicylaldehyde or 3,5-ditbutylsalicylaldehyde) in MeOH was added dropwise into the solution of amino sugar derivative in 5mL of MeOH. Schiff bases were synthesized at the last of reaction. For to perform Henry reaction; to a solution of shiff bases as a ligand and solvent at the given temperature was added Cu(OAc)2.nH2O. Then the aldehyde(4-nitrobenzaldehit) and nitromethane were added into the solution. Subsequential of the completion, to afford the desired Henry product the solvent was evaporated and the residue was purified by column chromatography using hexane:ethyl acetate. HPLC using a Chiralcel OD-H column used to determine the enantiomeric excess values. Spectroscopic analysis, like 1H-NMR, IR and13C-NMR, helped us to learn the structures of all the compounds.